It has already transformed the television viewing habits of millions and boosted ratings for a diverse cast of stars from Noel Fielding to Sir Alan Sugar and Jeremy Vine. Now the iPlayer, the online catch-up service which the BBC said yesterday had received more than 100m programme requests in just six months, is to undergo a wholesale revamp.

The new version of the service, available from today alongside the existing one, which will gradually be phased out, will improve picture quality, enable the creation of personalised channels and fully integrate radio for the first time.

It will also allow radio shows and television programmes to be cross-promoted and grouped by genre. The BBC hopes that this will make viewers aware of programmes that they would not normally watch.

The BBC's director of vision, Jana Bennett, has highlighted the way in which the iPlayer, which allows viewers to either stream their chosen shows immediately or download them to watch later, has changed viewing habits and boosted ratings for programmes that might otherwise be overlooked. Examples include the BBC3 comedy Gavin & Stacey, which attracts 7% of its viewers through the iPlayer, and The Mighty Boosh, the cult comedy, which gets up to 40% of its viewing through the service.

Programmes targeted at younger viewers have been particularly popular - the CBBC series M.I. High recorded a fifth of its viewing through the iPlayer - but a wide range of other shows have also been given a longer shelf life. The fifth most watched programme yesterday was Panorama's investigation into the use of child labour by suppliers of the clothing store Primark, originally broadcast on Monday.

Anthony Rose, the BBC's head of digital media technology, said the new iPlayer would recommend other programmes that viewers might enjoy, based on what they had already watched. It would also remember if they had stopped watching a programme before it had finished and allow them to resume watching at the same point.

Over the coming months, there would be more personalisation, Rose added, allowing viewers to register to access programmes chosen for them wherever they are. Other ideas include the ability to share programme recommendations with friends and request programmes via text message.

The BBC's on-demand radio service, which paved the way for the iPlayer when it launched in 2002 and has provided more than 600m hours of listening since, has also been overhauled.

Some programmes, such as Radio 1's Essential Selection, already get as many listeners via PCs as they do live on air. But as with the television service, there is a broad uptake. Other popular shows include The Archers and Melvyn Bragg's In Our Time.

The new version of the radio player will be integrated with the iPlayer and, following complex negotiations with record labels and rights bodies, will allow listeners to fast forward and rewind precisely through programmes. At present, they are limited to skipping forwards and backwards in five-minute bursts.

Erik Huggers, the BBC's group controller of future media and technology and favourite to become director of the division following the departure of Ashley Highfield, said the service would continue to evolve rapidly.

The majority of users access the iPlayer via their computer, but Huggers said that ultimately more people would use their television. The BBC already offers the iPlayer to Virgin Media's cable TV customers and owners of the Nintendo Wii console. It is negotiating with other internet television operators such as BT Vision and Tiscali.

Earlier this week, the BBC's director general, Mark Thompson, promised to collaborate with other broadcasters, ISPs and set-top box manufacturers to develop an open standard for internet TV. That could result in cheap set-top boxes that allow viewers to watch Freeview channels and on-demand services such as the iPlayer.

There is also a push to make the iPlayer available on more mobile devices after it launched on the Apple iPhone and iPod Touch earlier this year.

Joint venture

Huggers must also decide how best to integrate it with Kangaroo, a commercial joint venture between the BBC, ITV and Channel 4 that is due to launch later this year and will offer ad-supported and paid-for downloads of programmes.

The BBC also hopes to make much of its 80-year archive available online, either via commercial services or free via its website, and exploit it overseas.

Bennett last month outlined plans to create a homepage for every BBC TV or radio programme ever made, which will ultimately link to video content.

Executives view the iPlayer as a key plank of their plans to "future proof" the corporation and preserve the licence fee in the digital age.

Huggers said the BBC was also working on clearing the half of all programmes not currently included on the iPlayer for rights reasons. All its new sporting contracts, including Wimbledon, the Olympics and Euro 2008, were cleared for broadcast, he said, but US imports and movies have remained a stumbling block.

Global distribution

Media giants in the UK and around the world, including YouTube owner Google, Apple, News Corp and NBC, are jostling for position as they seek to find ways to benefit from global internet distribution.

The long-mooted iPlayer had been mired in internal regulatory and technological wrangles, allowing Channel 4 and ITV to steal a march on the BBC by launching their own on-demand services. Yet the teething troubles that beset the project have been largely forgotten amid huge consumer appetite for the iPlayer.

Users have 30 days to begin watching a show from the point at which they download it. At present 10 times as many programmes are streamed - or watched immediately - as are downloaded to watch later. But Rose said he expected the proportion of downloaded shows to increase as the facility was made available to Apple Macintosh users before the end of the year and more people opted to transfer shows to their laptop or portable device.